Iqbal F, Ast J, Göken M, Durst K (2012)
Publication Type: Journal article
Publication year: 2012
Book Volume: 60
Pages Range: 1193-1200
Journal Issue: 3
DOI: 10.1016/j.actamat.2011.10.060
In situ micro-cantilever tests were carried out to determine the anisotropic fracture toughness of NiAl single crystals. Notched micro-cantilever beams with a beam length of 8~\textgreekmm, 1.5~\textgreekmm thickness and 1.8~\textgreekmm width were milled in so-called ``hard'' and ``soft'' orientations of NiAl using a focused ion beam. These cantilevers were loaded in situ with the help of a cantilever-based nanoindenter mounted inside a scanning electron microscope. A fracture toughness of 3.52~$±$~0.29~MPa~m1/2 was obtained for the ``soft'' orientation and 5.12~$±$~0.50~MPa~m1/2 for the ``hard'' orientation, which is in good agreement with literature values on the fracture toughness of macroscopic NiAl specimens. Furthermore, nanoindentations were performed for studying the size effects occurring at small length scales for both orientations. The applicability of the small sample geometries for testing the fracture toughness is finally discussed in terms of size effects in the flow stress of the material due to dislocation nucleation and strain gradients at the crack tip.
APA:
Iqbal, F., Ast, J., Göken, M., & Durst, K. (2012). In situ micro-cantilever tests to study fracture properties of NiAl single crystals. Acta Materialia, 60(3), 1193-1200. https://doi.org/10.1016/j.actamat.2011.10.060
MLA:
Iqbal, Farasat, et al. "In situ micro-cantilever tests to study fracture properties of NiAl single crystals." Acta Materialia 60.3 (2012): 1193-1200.
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